Sorry that I can't help you out with where you could get Vacuum Pump oil on a sunday afternoon (short of stealing a bottle out one of the vacuum pump boxes at harbor freight)...
What I can suggest (which might help):
Is your vacuum pump really fancy? Would you be opposed to using a cheaper model? If you don't really care about the "quality" of the vacuum being drawn, you can always go down to your local autozone and rent (for some deposit between 100 and $200) one of their pumps, and procure the oil during the hours that a napa/grainger/&c. would be open. I don't think I've been to an Autozone in Florida (within the last 7 or 8 years) that didn't rent vacuum pumps. Might want to call for availability, though, in the event that a particular store's unit has been made unavailable.